A takeaway order is regarded as a distance selling transaction. In distance selling, allergen information must be provided both before the food is purchased (at the point of sale) and when it is delivered. It can be communicated in writing, online, through a catalogue, or over the phone.
Make sure to speak with the restaurant ahead of time when ordering for several people with allergies. Request that they label each meal and container with the allergies that are in that dish, so you can avoid any accidental exposure to something you’re allergic to. This will help to ensure that everyone’s experience is a positive one, and that everyone can enjoy their meal without fear of any potential reactions.